Table 3 Sex-specific mixed effects estimates on body mass index (BMI) of study population, coefficient (95% CI)

 Age

0.28(0.20, 0.35)

< 0.001

 Age²

−0.003(− 0.004, − 0.002)

< 0.001

 Phase III

1.68(1.06, 2.30)

< 0.001

 Phase V

1.60(0.41, 2.78)

0.008

 Phase III *age

−0.014(− 0.027, − 0.002)

0.028

 Phase V *age

− 0.005(− 0.028, 0.018)

0.662

Smoking (Ref: non-smoker)

− 0.38(− 0.57, − 0.19)

< 0.001

Physical activity (Ref: high)

0.16(0.05, 0.27)

0.005

Education (Ref: > 12 year)

−0.07(− 0.31, 0.16)

0.534

Spouse: (Ref: married)

−1.03(−1.30, − 0.77)

< 0.001

 Age

0.61(0.53, 0.69)

< 0.001

 Age²

−0.006(− 0.007, − 0.005)

< 0.001

 Phase III

−1.24(− 1.89, − 0.59)

< 0.001

 Phase V

−2.92(−4.20, − 1.65)

< 0.001

 Phase III *age

0.04(0.03, 0.05)

< 0.001

 Phase V *age

0.08(0.06, 0.11)

< 0.001

Smoking (Ref: non-smoker)

−0.69(−1.14, − 0.23)

0.003

Physical activity (Ref: high)

0.12(0.02, 0.23)

0.024

Education (Ref: > 12 year)

0.74(0.46, 1.03)

< 0.001

Marital status: (Ref: married)

−1.69(−2.03, − 1.35)

< 0.001